I now tested in PSP X3 and also found no problem. I suspect that you have some color management setting active that causes this. Please save the processed image and open it in Photoshop. Do you still see the yellow spots? If not, please change your color management settings or deactivate color management.

I see you mean PSP X3 Service Pack 3. So it lets you apply FocalBlade to 16-bit/channel images? Great to hear that! I have waited for that feature for years.

I suspect that PSP X3 uses 65536 values for 16-bit images whereas Photoshop only uses 32768 and PSP does not do an internal conversion to compensate for the problem. It should be possible to adjust our plugins to this special case.

Unfortunately when I apply the Service Pack patch to the PSP X3 trial version, it does not run anymore. Seems I have to get the full version first.

After fighting around with installing, patching and reinstalling PSP X3 for several hours under Windows XP, I gave up after PSP X3 did not want to install anymore. I tried it under Vista and patching worked instantly. Seems that PSP X3 really has problems under Windows XP. What a nuisance!

Anyway, the problem is that PSP X3 uses a value range of 0 to 32767 instead of 0 to 32768. As result pixel values of 32768 (pure white) are converted wrongly to yellow/green when converting back to the 0 to 65535 range. So after delaying this simple feature for many years, the Corel programmers even manage to do implement it incorrectly. Unbelievable!

Anyway, the problem is quite easily solved. I just sent you a fixed version of FocalBlade 2.